E.O. 12866 Review 2060-AQ-42 Email 011311+2 att.txt

From: Dave Guinnup/RTP/USEPA/US

To: Cortney_Higgins@omb.eop.gov, nancy beck <nbeck@omb.eop.gov>

Cc: Michael Stewart/RTP/USEPA/US@EPA

Date: 01/12/2011 11:30 AM

Subject: Fw: Part of E.O. 12866 Review: EPA Staff Response to "Supplementary Information for RTR -Primary Lead Smelting"additional documentation for model-to-monitor comparison [2060-AQ42]

Attachments: Lead Model to Monitor comparison.docx

here's the additional info you requested

(See attached file: Lead Model to Monitor comparison.docx)

Dave Guinnup Leader, Air Toxics Assessment Group Health and Environmental Impacts Division Office of Air Quality Planning and Standards US EPA (C539-02) Research Triangle Park, NC 27711 (919)-541-5368 voice (919)-541-0840 FAX

Page 1

### Primary Lead Smelter Model to Monitor Analysis

Considering calendar year 2008, we compared maximum AERMOD estimates of ambient lead

concentrations with those measured at 4 monitors in close proximity to the Herculaneum Primary Lead Smelting Facility. More sp ecifically, we compared maximum 3-month rolling average lead concentrations (for calendar year 2008) calculated from data repor ted at the Main Street, Circle Street, South Cross, and Church Street monitors to the maximum 3-month rolling average lead concentrations at model receptor locations in close proximity to these monitoring sites (see Figure 1 for location of monitors and AERMOD receptors). These monitor locations were chosen because they represented the closest offs ite monitors to the Herculaneum primary lead smelter. Thus, lead measurements at these monitoring sites would likely be dominated by emissions from this facility- which is important given that AERMOD estimates of ambient lead concentrations only considered lead emissions from this facility (i.e., only lead emissions from the Herculaneum primary lead smelter were used as inputs into AERMOD).

Results of this analysis are presented in Table 1 and indicate that with respect to the Main Street and Circle Street monitors, AERMOD underestimat es 3-month maximum lead concentrations by approximately 4.6- and 3-fold respectively. With respect to the South Cr oss and Church Street monitors, AERMOD overestimates 3-month maxi mum lead concentrations by approximately 2.8- and 4.2-fold, respectively. Moreover, re sults also indicate that the maximum 3-month average lead concentration calculated from any of these monitors is approximately equal to the maximum 3-month average lead concentrati on estimated by AERMOD at any of these monitoring sites (i.e., both th e Main Street monitor and the South Cross AERMOD estimate indicate the maximum 3-month average lead concentration to be approximately 2.1 μgs/m 3 

### ). Taken together, these results indicate that AE RMOD estimates of ambient lead concentration

1 Maximum 3

‐ month monitored concentrations were calculated for the year 2008 based on data submitted to EPA’s Air Quality System (AQS).

2 Negative sign denotes an underestimation of AERMOD modeled ambient lead concentrations, relative to monitored concentrations. AERMOD estimated concentrations were based on 2008 emissions estimates. 

### Table 1. Comparison of AERMOD modeled to am bient lead concentrations reported by six monitors surrounding the Herculaneum Primary Lead Smelting Facility.
Location Maximum AERMOD Modeled 3-Month Lead Concentration (μgs/m 3 

### ) Maximum Monitored 3- Month Lead Concentration 1 

### (μgs/m 3 

### ) Model to Monitor Ratio 2



### Main Street 0.47 2.14 -4.6
Circle Street 0.38 1.14 -3.0
South Cross 2.13 0.75 2.8 Church Street 1.99 0.47 4.2

### provide a reasonable representa tion of the measured 3-month maximum lead concentrations present in the ambient ai r near this facility

Figure1. Monitor Locations, Discreet Recepto rs and Maximum Risk Receptors for the Doe Run Herculaneum Primary Lead Smelter